Ensure System Safety with GSN

GSN, or Goal Structuring Notation, is a technique to visualize how goals of a system are successively broken down into sub-goals until a point is reached where claims can be supported by direct reference to available evidence. GSN has been increasingly used for safety cases in industries such as automotive (ISO 26262), aerospace (DO-178B), rail, nuclear, and defense. If you require GSN modeling, Astah System Safety is the right choice for your system safety assurances.

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Create GSN diagram with Astah


If you need a GSN modeling tool, Astah System Safety is the right choice because Astah is not just a drawing tool. For example, Astah compliant with the GSN Community Standard version 1.0 and supports OMG SACM (ARM) import/export. You are able to create the Modules. You can also specify the Modules and the Public Indicators, connect the models by using the SupportedBy and the InContextOf.

Make drawing GSN faster and easier


You can create the Goal just by double-clicking on the diagrams. Also the mini-icon called “Suggest Feature” appears when you hover over a model so that you can create the model with a single click.  Astah has a variety of other functions to make your work easier, include:

Export diagram as image
API Support
Integrate with MindMap

One-click for a clean diagram


Drawing clean diagrams makes sharing with others more accurate. With Astah, you can draw the clean diagram with a single click. Astah has an “Auto-Layout” feature that lets you automatically lay out the GSN diagram nicely at the finish-up.

Easy access to models via scripts


You can easily access the GSN models by using Script Editor. When you run the script within-app, Astah performs customized operations such as count the Goals or check whether the Goal has the Solutions in a project. Sample scripts are available.

Support for team development


For team use, the “Compare” and “Merge” features enables you to compare models and diagrams in two project files and see the differences in a list and also visually with markups. After you compare two diagrams, you can merge one project file to another. So that you can divide the work among the team members and merge them into one file.

Integrate with SysML


Astah System Safety is an all-in-one tool that can draw not only GSN but also SysML and STPA/STAMP. So you can convert SysML models into GSN models, such as Requirement to Goal. Hyperlinks between the models are added for traceability. You can also synchronize Requirements and Goal. By synchronizing two models, when you edit one, the changes are reflected in the other.


The use of assurance cases is becoming increasingly widespread in the development and assessment of high integrity systems across many domains (e.g. medical, process industries, nuclear, automotive, transportation and defence). For example, the new automotive safety standard ISO26262 requires the production of a safety case. GSN is an important technique in helping construct and present clear assurance case arguments. It’s great to see tools such as astah* GSN – built on top of the SACM and GSN standard, bring tool support for GSN to the growing worldwide community of GSN users, including Japan.

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